.page-container {
    max-width: 750px;
    margin: 0 auto;
    position: relative;
}

.section {
    min-height: 100vh;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    overflow: hidden;
}

.music-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    cursor: pointer;
    border: none;
    transition: transform 0.3s;
}

.music-btn.playing {
    animation: rotate 3s linear infinite;
}

.music-btn svg {
    width: 18px;
    height: 18px;
    fill: var(--primary-color);
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }

.toast {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.7);
    color: var(--white);
    padding: 12px 25px;
    border-radius: 25px;
    font-size: 14px;
    letter-spacing: 2px;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.toast.show {
    opacity: 1;
}

.back-top {
    position: fixed;
    bottom: 30px;
    right: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border: none;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}

.back-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-top svg {
    width: 18px;
    height: 18px;
    fill: var(--primary-color);
}

.particles-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 50;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 8px;
    height: 8px;
    background: var(--gold);
    border-radius: 50%;
    opacity: 0;
    animation: particleFloat 3s ease-out forwards;
}

@keyframes particleFloat {
    0% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
    100% {
        opacity: 0;
        transform: translateY(-100px) scale(0);
    }
}

.scroll-indicator {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: rgba(196, 149, 106, 0.1);
    z-index: 100;
}

.scroll-indicator-bar {
    height: 100%;
    background: var(--primary-color);
    width: 0%;
    transition: width 0.1s;
}

@media (min-width: 750px) {
    .cover-frame {
        width: 340px;
        height: 450px;
    }

    .cover-title {
        font-size: 42px;
    }

    .cover-name {
        font-size: 38px;
    }

    .gallery-item {
        width: 300px;
        height: 400px;
    }
}